The HardyâWeinberg principle provides the solution to how variation is maintained in a population with Mendelian inheritance. According to this principle, the frequencies of alleles (variations in a gene) will remain constant in the absence of selection, mutation, migration and genetic drift.
Rxâd â A definition: A lot of new Crossfitters come in and ask âwhat does the Rxâd mean that everyone puts in their posts?â This is a very valid question and one that everyone should be thinking about. This post is to clearly define why one uses âRxâdâ. Rxâd simply means âas prescribedâ.
Resistance transfer factor (shortened as R-factor or RTF) is an old name for a plasmid that codes for antibiotic resistance. R-factor was first demonstrated in Shigella in 1959 by Japanese scientists. Often, R-factors code for more than one antibiotic resistance factor: genes that encode resistance to unrelated antibiotics may be carried on a single R-factor, sometimes up to 8 different resistances.